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A  gjic .  -  Forestry .  Main  Li\)rar> 


Aerie. -Forestry.  Main  Library.  •  :  •.  ; 


UNITED  STATES  DE 


Washington,  D.  C. 


August,  1922 


EXPERIMENTS    WITH    SPRAY    SOLUTIONS    FOR 
PREVENTING  INSECT  INJURY  TO  GREEN  LOGS. 

By    F.    C.    CBAIGHEAD.1 

in    Forest    Entomology,    Forest    Insect    Investigations,    Bureau    of 
Entomology. 


CONTENTS. 


Page. 

ses  for  repellent  sprays  against  for- 
est and  shade-tree  insects 1 

equisites  of  a  practical  spray 3 

It  must  be  effective   against  sev- 
eral types  of  insects 3 

It    must    be    effective    on    various 

species  of  wood 4 

It  must  not  be  leached  off  by  rain 

or  other  weather  conditions 4 

It  must  not  be  expensive. _.  4 


(Requisites  of  a  practical  spray — Con. 
It  must  first  prevent  all  insect  in- 
jury   for    from    one    to    three 

months  at  least 

^Experiments  with,  preventive  sprays__ 

Treatments   and   results 

Remarks  on  poisons  used . 

Other  experiments  with  insects  of 

type3 

Poisoning  of  ambrosia  beetles 


4 

4 

7 
1O 

10 
11 


rSES   FOR   REPELLENT   SPRAYS   AGAINST   FOREST   AND    SHADE- 

TREE  INSECTS. 

During  the  past  few  years  there  has  been/an  increasing  demand  for 
practical  spray  that  "will  prevent  insect  attack  to  crude  forest  prod- 
cts  such  as  green  sa/w  logs  and  timbers  used  in  rustic  construction, 
lumerous  requests  for  such  a  spray  are  received  by  the  Bureau  of 
Intomology.  These  inquiries  often  number  more  than  a  hundred 
irough  the  summer  months. 

Although  many  lumbering  firms  request  a  spray  for  this  purpose, 
;  is  doubtful  whether  it  would  be  really  practical  under  ordinary 
onditions.  During  the  flight  period  of  those  insects  which  cause  the 
ijury  it  would  be  necessary  to  apply  the  spray  immediately  after 
illing  the  trees.  It  is  more  practical  to  prevent  insect  injury  in  lum- 
ering  operations  by  some  alteration  in  the  methods  of  management, 
3  by  more  prompt  handling  between  felling  and  sawing  or  by  sub- 
icrging  the  logs  in  water,  than  by  spraying. 


1  Resigned  December  31,  1920. 
102230—22 1 


2  BULLtfT^  407^.11..$^  DEPARTMENT   OF   AGRICULTURE. 

**»••*•   •* *  •  •**••      !•**. 

•    •       •  •••••*,•  . 

Frequently,  however,  storms  blow  over  many  millions  of  feet  of 
saw  timber.  Cases  are  on  record  where  a  single  firm  has  lost  in  such 
a  manner  100,000,000  board  feet.  It  is  a  physical  impossibility  to  log 
these  trees  promptly  and  get  them  to  the  saw  or  into  a  place  of  safety, 
although  from  40  to  60  days'  delay  may  mean  total  destruction  of  the 
sapwood  by  borers.  It  might  be  feasible,  however,  to  saw  these  trees 
into  log  lengths  and  spray  with  some  solution  that  would  prevent 
insect  attack  for  two  or  three  months,  or  until  it  was  possible  to  haul 
them  to  the  mill. 

The  increasing  use  of  the  national  forests  and  parks  for  recrea- 
tional  purposes  has  resulted  in  the  construction  of  many  rustic  cabins. 
Insects  attacking  the  timbers  in  these  buildings  cause  annoying  exu- 
dations of  boring  dust  and  loosen  the  bark  so  that  later  it  peels  off, 
thus  marring  the  artistic  effect.  Much  of  this  injury  to  rustic  work 
could  be  prevented  by  cutting  the  trees  at  certain  periods  and  by 
proper  seasoning.  Frequenters  of  summer  camping  grounds  can  not 
always  plan  to  cut  the  trees  at  the  proper  time;  in  fact,  it  is  more 
frequently  the  case  that  the  building  is  constructed  during  the  sum- 
mer months  and  the  timber  felled  at  that  time — a  period  when  the 
wood  is  most  susceptible  to  insect  attack. 

Thus  in  both  situations  it  is  often  the  case  that  the  more  practical 
and  economical  means  can  not  be  used. 

There  is.  also  a  considerable  demand  for  a  suitable  repellent  spray 
against  certain  shade-tree  insects.  Wood  borers  attack  various  spe- 
cies of  living  trees,  causing  considerable  injury  or  death.  Under 
certain  circumstances  a  spray  could  be  used  advantageously  to  repel 
such  insects  and  prevent  oviposition.  It  would  necessarily  have  to 
be  of  materials  that  would  not  burn  the  younger  bark,  although, 
except  for  mechanical  difficulties,  it  would  only  be  necessary  to  apply 
the  spray  to  the  main  trunk  and  larger  limbs,  $ince  these  are  the  only 
parts  attacked.  Spray  materials,  the  cost  ofVwhich  would  be  pro- 
hibitive for  the  protection  of  forest  products,  nlight  be  employed  on 
shade  trees. 

Under  circumstances  such  as  the  foregoing  it  is  evident  that  a 
"practical  spray  for  the  prevention  of  insect  injury  would  be  of  much 
benefit  and  its  use  should  result  in  a  considerable  saving  of  forest 
products  and  shade  trees. 

Owing  to  the  many  different  insects,  their  different  methods  of 
attacking  the  logs,  the  many  kinds  of  wood  to  be  protected,  and  the 
exposure  to  weather  conditions,  the  practical  solution  of  this  prob- 
lem presents  many  difficulties.  Several  solutions  have  been  found 
to  meet  the  requirements,  except  that  they  are  too  expensive  or  too 
difficult  to  apply.  In  the  hope  that  the  results  so  far  obtained  may 
be  a  stimulus  for  further  suggestions  or  work  along  this  line  the 


EXPERIMENTS  WITH  SPR  ASOLUTIONS    l.^i;  /VREEN  LOOS.  3 

problem    and  the   preliminary1  '  Vx'pcr'iAents  conducted   during   the 
years  191G  to  1919  are  here 


REQUISITES  OF  A  PRACTICAL  SPRAY. 

It  may  be  impossible  to  find  a  single  spray  solution  that  can  be 
used  with  success  under  all  conditions,  but  it  may  be  possible  to 
obtain  good  results  by  using  several  solutions,  each  of  which  is  effec- 
tive under  certain  conditions.  Any  spray  to  fulfill  all  the  requisites 
necessary  for  practical  effectiveness  must  possess  the  following  qual- 
ities : 

IT    MUST    BE    EFFECTIVE    AGAINST    SEVERAL    TYPES    OF    INSECTS. 

Many  species  of  insects  attack  green  timber.  Some  attack  only 
certain  kinds  of  wood  while  others  show  little  discrimination.  In 
some  cases  the  injury  is  caused  by  the  grubs  or  larvae  feeding  be- 
neath the  bark  or  in  the  wood,  or  by  an  adult  which  bores  through 
the  bark  and  produces  larvae  that  feed  under  the  bark.  According 
to  their  method  of  attacking  the  wood,  boring  insects  may  be  divided 
into  the  following  four  groups  : 

Type  1.  Those  that  lay  eggs  in  crevices  of  the  bark.  The  larvae 
hatching  from  these  eggs  then  bore  through  the  bark  and  later  into 
the  wood. 

Type  2.  Those  that  gnaw  a  hole  through  the  bark  and  insert  the 
egg  beneath.  The  larvae  start  feeding  directly  beneath  the  bark  and 
later  bore  into  the  wood. 

Type  3.  Those  that  bore  through  the  bark  and  wood  as  beetles, 
to  make  a  suitable  place  for  developing  a  new  brood.  The  grubs  in 
this  case  never  cause  injury. 

Type  4.  Those  that  bore  through  the  bark  as  beetles  and  lay  the 
eggs  beneath  the  bark.  The  resulting  larvae  feed  beneath  the  bark 
and  loosen  it. 

The  only  spray  that  could  possibly  be  effective  against  all  these 
types  would  be  one  of  a  disagreeable  odor  acting  as  a  repellent,  thus 
driving  away  the  adult  beetles  and  preventing  oviposition.  Poison 
sprays  that  will  penetrate  the  outer  layers  of  bark  will  kill  the  young 
larvae  of  type  1,  but  experiments  have  demonstrated  that  such  mate- 
rials are  not  effective  against  types  2,  3,  and  4..  In  these  types  most 
of  the  beetles  do  not  eat  any  of  the  bark  or  wood  as  they  chew 
through  it  and  consequently  are  not  poisoned.  Possibly  a  poison 
combined  with  a  sticky  substance  that  would  form  a  film  over  the 
bark  and  adhere  to  the  mouth  parts  of  the  insects  might  kill  them. 

Insects  of  type  4  are  not  very  injurious  to  saw  logs,  as  they  only 
work  beneath  the  bark  and  do  not  enter  the  wood,  but  they  are 
important  in  loosening  the  bark  from  rustic  work.  The  others  are 
all  injurious  to  both  classes  of  timber. 


4  BULLION.  1079,   U/ S/ DEfcART^ENT   OF   AGRICULTURE. 

IT   MUST  *Bfi  *EfFECTrv:E> -ON 'VARIOUS    SPECIES    OF    WOOD. 

The  type  of  bark  makes  considerable  difference  in  the  application 
of  a  spray.  A  bark  which  is  very  absorbent,  such  as  that  of  ash  or 
juniper,  readily  takes  a  spray;  on  the  other  hand,  a  smooth  bark, 
such  as  beech  or  hickory,  will  absorb  scarcely  any  of  it.  Such  smooth 
bark  does  not  hold  the  spray  well  but  allows  it  to  be  easily  washed 
off  in  the  rain.  In  the  latter  case  poison  sprays  would  hardly  be 
effective.  The  irregularities  of  the  bark  and  all  crevices  must  be 
thoroughly  covered. 

IT  MUST  NOT  BE  LEACHED  OFF  BY  RAIN  OR  OTHER  WEATHER  CONDITIONS. 

One  of  the  greatest  difficulties  in  the  experiments  to  find  an 
effective  spray  has  been  that  the  solutions  are  soon  washed  off  by 
rain.  Many  of  those  tried  were  effective  for  a  few  weeks,  or  until 
the  first  hard  rain,  after  which  the  trees  were  immediately  attacked. 

IT  MUST   NOT  BE  EXPENSIVE. 

Since  a  considerable  quantity  of  liquid  is  required  to  cover  a 
large  log  by  spraying,  it  naturally  follows  that  the  material  must 
be  inexpensive  or  it  can  not  be  used.  Creosote  oil,  the  most  effective 
material  so  far  tried,  is  far  too  expensive.  It  can  be  diluted,  how- 
ever, with  as  much  as  4  parts  of  kerosene,  thus  materially  reducing 
the  cost  of  the  spray  without  diminishing  its  effectiveness.  For  rus- 
tic work  a  much  more  costly  spray  can  be  used  than  on  logging  op- 
erations. 

IT    MUST    FIRST    PREVENT    ALL    INSECT    INJURY    FOR    FROM    ONE    TO    THREE 

MONTHS  AT  LEAST. 

Three  months'  protection  by  the  spray  would  be  sufficient  for  most 
purposes.  It  is  usually  possible  to  get  logs  to  the  mill  or  into  a 
place  of  safety  within  that  time.  If  it  were  sufficiently  cheap  so 
that  a  second  and  perhaps  a  third  application  could  be  made,  the 
solution  would  need  to  be  effective  for  only  one  month ;  the  necessity 
for  more  than  one  application,  however,  would  of  course  be  a  handi- 
cap. In  many  cases  three  months'  prevention  of  damage  would  carry 
the  tree  or  log  through  the  danger  period — that  in  which  the  insect 
is  flying — and  natural  seasoning  during  the  ensuing  winter  would 
prevent  further  injury. 

EXPERIMENTS  WITH  PREVENTIVE  SPRAYS. 

During  the  period  of  insect  activities  in  the  years  1916  to  1920, 
inclusive,  series  of  experiments  were  conducted  at  the  Eastern  Field 
Station  of  the  Bureau  of  Entomology,  East  Falls  Church,  Va.,  to 
determine  the  effectiveness  of  various  solutions.  These  were 


EXPERIMENTS  WITH  SPR^      SOLUTINS*  JSpR,  SREEN  LOGS.  5 

materials  recommended  by  va'fio'us*  correspondents  or  suggested  by 
the  forest  insect  personnel.  Dr.  J.  K.  Haywood,  chairman  of  the 
Insecticide  and  Fungicide  Board,  United  States  Department  of 
Agriculture,  also  gave  some  very  interesting  suggestions. 

These  experiments  are  to  be  considered  as  only  of  a  preliminary 
character.  The  objects  were  chiefly  to  determine  the  requisites  of 
an  effective  spray  and  to  study  the  behavior  of  the  different  types 
of  insects  in  relation  to  various  treatments  and  methods  of  applica- 
tion, as  well  as  to  find  an  effective  spray. 

The  solutions  were  tried  principally  on  two  kinds  of  wood — pine 
and  ash — although  occasionally  hickory,  juniper,  and  oak  were  used. 
The  wood  was  cut  at  a  time  to  give  the  most  favorable  condition 
for  insect  attack — hickory  and  juniper  about  January  1,  pine  and 
ash  about  March  15.  It  was  treated  immediately  or  held  in  a  wire 
insectary  until  treated.  The  individual  pieces  of  wood  used  were 
3  feet  long  and  averaged  from  6  to  10  inches  in  diameter. 

Insects  of  all  types  were  represented  in  the  tests.  The  following 
were  the  most  abundant  and  economically  the  most  important: 
Neoclytus  erythrocephalus  Fab.  on  ash  and  hickory,  Xylotrechus 
colonus  Fab.  on  oak  and  hickory,  Aserrwm  moestimi  Hald.  on  pine, 
Cyllene  pictus  Drury  on  hickory,  and  Hylotrupes  ligneus  Fab.  on 
juniper — all  of  type  1 ;  M  onohammus  scutellatus  Say  and  M.  titillator 
Fab.  on  pine — both  of  type  2  (no  species  of  type  2  on  other  woods)  ; 
various  species  of  Ips,  Phloeosinus,  and  Hylesinus  on  pine,  juniper, 
and  ash,  respectively — of  type  4;  various  species  of  ambrosia  beetles 
on  pine  and  oak  of  type  3. 

From  the  foregoing  it  is  seen  that  pine  was  tested  against  all  four 
types;  ash  against  types  1,  3,  and  4;  hickory  against  type  1;  juniper 
against  types  1  and  4 ;  and  oak  against  types  1  and  3.  Owing  to  the 
seasonal  variations  in  the  abundance  of  the  various  species  of  insects 
the  tests  were  not  conclusive  every  season.  For  example,  in  1918  and 
1919  Monohammus  was  very  abundant  and  attacked  all  the  controls 
as  well  as  many  treated  woods,  while  in  1920  very  few  were  present 
and  not  all  control  logs  were  attacked.  Again,  in  1918  Hylesinus 
(type  4)  in  ash  was  abundant,  though  in  1920  very  few  of  the  con- 
trol logs  were  attacked.  Every  year,  however,  some  one  type  was  very 
abundant  on  all  species  of  wood  used. 

The  flight  period  of  these  insects  has  a  certain  bearing  on  the  re- 
sults, as  those  species  flying  late  in  the  season  found  the  logs  after 
they  were  exposed  to  weathering  for  a  month  or  more.  Most  of  the 
treatments  were  made  about  April  1,  or  15  days  before  the  flight  of  the 
first  insects,  and  unless  otherwise  stated  this  time  of  treatment  is  to 
be  inferred.  With  certain  materials  treatments  were  made  also  on 
June  1  at  the  time  of  the  first  flight  of  some  other  species.  The  flight 
periods  are  given  in  Table  I. 
102230—22 2 


6 


OF   AGRICULTURE. 


TABLE  I. — Flight  periods  of  beetles  used  in  experiments  for  the  protective  treat- 
ments of  woods  with  spray  solutions. 


Apr. 

May. 

June. 

July. 

Aug. 

Sept. 

Oct. 

Woods. 

Asemum  moestum,  type  1. 

•MMW 

Pine. 

Monohammus  titillator  and  M. 

Pine 

scutellatus,  type  2  . 

Phloeosinus,  Hylesinus,  and  Ips, 

type  4. 

Cyllen.e  pictus,  type  1. 

•••^H 

~mmv—m~* 

Hickory. 

Hylotrupes  hgncus,  type  1. 



Juniper. 

In  the  extreme  northern  States  the  flight  period  of  these  insects- 
begins  from  two  to  four  weeks  later.  In  the  Southern  States  the 
flight  period  extends  approximately  from  March  15  to  November  1 
for  all  species  except  Cyllene  pictm. 

Two  methods  of  application  were  employed — spraying  and  dip- 
ping. Dipping  on  the  whole  proved  the  more  effective,  as  e very- 
crevice  in  the  bark  was  reached;  it  was  also  more  economical,  as  a 
smaller  quantity  of  the  solution  was  required.  A  round-bottomed 
galvanized  trough  requiring  only  1  inch  of  solution  in  the  bottom 
was  used  for  this  purpose.  The  logs  were  revolved  in  the  trough 
until  all  sides  came  in  contact  with  the  liquid.  When  carefully  doner 
however,  spraying  was  nearly  as  effective  as  dipping  and  answered 
very  well  for  practical  purposes.  It  required  a  fine  discharge  under 
strong  pressure  so  that  penetration  in  all  crevices  was  secured. 

The  treated  sticks  were  placed  in  several  positions:  (1)  In  shaded 
woods  on  the  ground,  (2)  in  the  sun  on  the  ground,  and  (3)  on  a 
platform  off  the  ground  in  the  sun.  The  location  of  the  sticks  had 
considerable  bearing  on  the  results.  Those  in  the  woods  were  always 
more  heavily  attacked  and  those  off  the  ground  in  the  sun  least  at- 
tacked. This  can  be  explained  by  the  more  rapid  seasoning  of  the 
wood  off  the  ground  in  the  sun,  which  thus  offered  less  favorable  con- 
ditions for  beetle  attack,  and  by  the  fact  that  many  insects  will  not 
oviposit  on  the  upper  surface  of  logs  directly  exposed  to  the  sun. 
The  logs  in  the  woods  were  likewise  exposed  to  more  humid  condi- 
tions and  the  solutions  probably  leached  off  sooner.  It  follows  that 


EXPERIMENTS  WITH  SPE>Y 


LOGS. 


the  most  severe  conditions  for  dipping  and  spraying  tests  were  pre- 
sented by  those  logs  in  the  woods  on  the  ground,  and  for  this  reason 
the  discussion  of  results  obtained  is  based  on  the  results  in  treated 
wood  placed  in  this  position.  Where  there  was  marked  difference  in 
the  amount  of  sunlight  or  in  the  sun  temperature  special  note  is  made 
of  the  fact. 

The  thickness  of  the  bark  had  a  certain  bearing  on  the  results. 
Thick-barked  pine  logs  present  much  more  favorable  conditions  for 
the  attack  of  all  insects  concerned.  In  some  cases  a  treatment  was 
very  effective  on  thin-barked  pine  logs  whereas  treated  thick-barked 
logs  became  Heavily  infested.  The  effectiveness  of  a  treatment,  there- 
fore, was  judged  by  the  results  following  in  the  case  of  thick-barked 
logs. 

TREATMENTS  AND  RESULTS. 

Creosote  oil  alone.  —  Pine  and  hickory  dipped  and  sprayed.  No  attack  three 
months  after  treatments  except  a  few  insects  of  type  4  in  crevices  of  sprayed 
stick. 

Creosote  oil  and  kerosene.  —  All  mixtures  of  kerosene  and  creosote  oil  give  a 
tarry  precipitate  which  must  be  strained  out  or  allowed  to  settle  before  the 
liquid  is  used  in  a  spray  pump.  This  material  was  suggested  by  Dr.  A.  D. 
Hopkins. 

Equal  parts  creosote  oil  and  kerosene.  —  Pine,  ash,  juniper,  and  hickory, 
sprayed  and  dipped.  Results  as  in  the  case  of  creosote  oil  alone. 

One  part  creosote  oil  and  two  parts  kerosene.-  —  Treatment  as  in  the  next  pre- 
ceding paragraph.  Results  as  in  the  case  of  creosote  oil. 

One  part  creosote  oil  and  three  parts  kerosene.  —  Pine  logs  dipped.  No  attack 
after  three  months. 

One  part  creosote  oil  and  four  parts  kerosene.  —  Pine  logs  dipped.  No  attack 
after  three  months. 

One  part  creosote  oil  and  eight  parts  kerosene.  —  Pine  logjs  sprayed  and  dipped 
were  attacked  after  two  months  by  a  few  insects  of  type  4. 

Creosote  oil  alone  and  mixtures  of  creosote  oil  and  kerosene  gave  excellent 
results.  Everything  considered,  much  better  results  were  obtained  with  them 
than  with  any  other  material.  Dilutions  of  creosote  oil  containing  from  1  to  as 
many  as  8  parts  of  kerosene  were  effective,  and  perhaps  an  even  greater  dilu- 
tion would  be  effective  on  absorbent  barks  such  as  ash  or  juniper.  These  mix- 
tures act  as  repellents  (in  no  cases  were  insects  observed  to  oviposit  where  the 
liquid  was  present)  and  they  "stand  up"  very  well  in  wet  weather. 

One  part  water-gas  tar  distillate*  and  three  parts  kerosene.  —  Considerably 
more  precipitate  results  from  this  mixture  than  from  that  of  creosote  oil  and 
kerosene;  consequently  it  is  more  troublesome  to  handle.  Pine  logs  were 
sprayed  and  dipped.  The  results  were  similar  to  those  with  creosote  oil. 

One  part  coal-tar  road  surfacing  material  and  three  parts  kerosene.  —  Pine 
logs  dipped  with  this  mixture  were  attacked  after  15  days  by  insects  of  type 
4  and  later  their  condition  was  but  little  better  than  that  of  the  controls. 

2  A  distillate  prepared  from  water  gas. 


8  BULLEtfTIK.  Ijfiify  Ttf..g,.DEPAR^ENT   OF   AGRICULTURE. 

Coal-tar  emulsion  (prepared  by'Ynsectictde  Board);  1  part  emulsion  to  10 
parts  water. — Pine  logs  dipped  and  sprayed  were  attacked  after  15  days  by 
insects  of  type  4  and  later  by  those  of  all  types.  Final  results  were^  no  better 
than  in  the  case  of  the  controls. 

Crude  petroleum. — Pine  logs  sprayed  and  dipped  with  crude  petroleum  were 
attacked  by  insects  of  type  4  after  15  days  and  later  by  those  of  all  types. 
Final  results  were  no  better  than  with  the  controls. 

Anthracene  oil  emulsio-n  (prepared  by  Insecticide  Board);  1  part  emul- 
sion to  10  parts  water  and  1  part  emulsion  to  100  parts  water. — Dipped  pine 
logs  were  attacked  by  insects  of  type  4  after  15  days  and  later  by  those  of  all 
types.  The  final  results  were  no  better  than  with  the  controls. 

Crude  solvent  naphtha. — Pine  logs  dipped  with  this  material  were  slightly 
attacked  by  insects  of  type  4  after  15  days  and  later  by  all  types.  Final 
results  were  but  little  better  than  with  the  controls. 

Six  ounces  of  nitrobenzene  in  one  gallon  of  kerosene. — Pine  logs  sprayed 
and  dipped  were  attacked  after  15  days  by  a  few  insects  of  type  4  and  later 
by  more  of  the  same  type.  The  final  results  were  somewhat  better  than  with 
the  controls. 

Fish  oil. — Pine  logs  sprayed  and  dipped  were  immediately  attacked  by 
insects  of  type  4  and  later  by  all  types.  Final  results  were  no  better  than 
with  the  controls. 

Two  parts  fish  oil,  one  part  pine  oil,  and  three  parts  kerosene. — Pine  logs 
sprayed  and  dipped  were  attacked  after  15  days  by  insects  of  type  4  and  later 
by  all  types.  The  final  results  were  no  better  than  with  the  controls. 

Kerosene. — Pine  logs  sprayed  and  dipped  were  attacked  after  15  days  by 
insects  of  type  4  and  later  by  all  types;  results  were  no  better  than  with  the 
controls. 

Sulphite  concentrate  (furnished  by  a  paper-pulp  null) ;  full  strength  an,d 
diluted  with  equal  parts  of  water. — Pine  logs  dipped  were  attacked  after  one 
week  by  insects  of  type  4  and  later  by  all  types.  Final  results  were  no  better 
than  with  the  controls. 

Spent  sulphite;  full  strength  and  equal  parts  spent  sulphite  and,  a  commercial 
miscible  oil. — The  results  in  pine  logs  dipped  and  sprayed  were  the  same  as 
with  sulphite  concentrate. 

Tree  ffum  (furnished  by  Gipsy  Moth  Laboratory)  ;  1  pound  of  tree  gum 
dissolved  in  1  quart  of  turpentine. — Pine  logs  treated  with  a  brush  were  at- 
tacked by  a  few  insects  of  type  4  after  two  months.  The  results  were  much 
better  than  on  the  controls,  but  the  material  held  moisture  in  the  log  and  pro- 
duced much  bluing  of  sap  when  insects  penetrated  the  bark.  The  sticky  film 
acted  as  a  mechanical  barrier. 

One  pound  of  melted  paraffin  with  one  gallon  of  gasoline  added. — Pine,  ash, 
and  juniper  logs  were  sprayed  and  clipped  and  placed  in  a  cage  for  experiment 
against  insects  of  type  4.  This  treatment  prevented  all  attack  on  the  more 
absorbent  bark  of  ash  and  juniper.  A  few  insects  attacked  the  pine. 

One-half  pound  of  naphthalene  dissolved  in  one  gallon  of  gasoline. — Dipped 
pine  logs  were  attacked  after  15  days  by  insects  of  type  4  and  later  by  all.  Final 
results  were  but  little  better  than  with  the  controls.  The  naphthalene  soon 
evaporates  and  no  odor  is  left. 

One  pound  of  melted  paraffin  with  one-half  pound  of  naphthalene  and  one 
gallon  of  gasoline  added. — Pine,  ash,  and  juniper  sprayed  and  dipped  and 
placed  in  a  cage  against  type  4  were  attacked  by  insects  of  this  type  after  30 
days. 


EXPERIMENTS  WITH  SPRAY  'SOLUTIONS  f.0$  QFEEN  LOGS.  9 


One  per  cent  sodium  arsenate  Svttftioh'—  JUniper  logs  dipped  and  exposed 
against  insects  of  types  1  and  4  were  not  attacked  after  60  days.  ^ 

Sixteen  parts  of  1  per  cent  sodium  arsenate  and  one  part  of  a  commercial 
miscible  oil.  —  Juniper  dipped  in  this  mixture  was  not  attacked  after  60  days, 
but  dipped  pine  was  heavily  infested  by  type  4  after  15  days. 

Stock  solution  of  kerosene  emulsion,  the  water  used  containing  2  per  cent 
sodium  arsenate.  —  Pine  and  hickory  logs,  sprayed,  were  attacked  by  all  types 
possible.  The  final  results  were  no  better  than  with  the  controls. 

One  ounce  of  sodium  arsenate  dissolved  in  one  pint  of  alcohol  and  added  to 
one  and  one-half  gallons  of  kerosene.  —  Very  little  arsenate  went  into  solu- 
tion. Pine  logs,  sprayed  and  dipped,  were  heavily  attacked  after  30  days 
by  insects  of  type  4  and  later  by  all  types.  Final  results  were  but  little  better 
than  in  controls.  Ash  logs,  sprayed  and  dipped,  were  attacked  by  one  insect 
of  type  1,  but  the  final  condition  was  much  better  than  with  the  controls. 
This  treatment  was  repeated  on  June  1  under  similar  conditions  and  with 
similar  results. 

One  part  arsenic  acid  to  nine  parts  water  followed  by  lime  water  (arsenic 
acid  30  per  cent  AS2Os  by  weight,  8.  G.  1.3000,  prepared  by  Insecticide  and 
Fungicide  Board.  —  Pine  and  ash  logs  were  dipped.  The  pine  was  not  attacked 
until  60  days  and  then  by  only  a  few  insects  of  type  4.  The  ash  was  not 
attacked.  This  treatment,  under  similar  conditions,  was  repeated  June  1,  and 
there  was  no  attack  after  60  days. 

One-fourth  ounce  of  corrosive  sublimate  dissolved  in  two  and  one-half  ounces 
of  alcohol  and  added  to  one  and  one-half  gallons  of  kerosene.  —  Pine  and  ash 
were  sprayed  and  dipped.  The  pine  was  first  attacked  after  40  days  by  a  few 
insects  of  type  4  ;  there  was  no  other  attack.  The  ash  was  not  attacked.  This 
treatment,  repeated  June  1  under  similar  conditions,  gave  the  same  results. 
Although  these  logs  were  not  attacked  by  Monohammus  of  type  2,  it  is  hardly 
safe  to  conclude  that  this  treatment  would  always  be  effective  against  them. 

Saturated  solution  of  sodium  fluorid.  —  Pine,  ash,  and  hickory  were  sprayed 
and  dipped.  There  was  no  attack  for  30  days,  and  then  the  logs  were  infested 
by  all  types,  though  to  a  less  degree  than  the  controls.  Little  bluing  was  noted 
on  pine.  Although  not  altogether  successful,  this  solution  is  worthy  of  further 
trial.  This  treatment,  repeated  June  1  with  conditions  as  before,  gave  like 
results. 

Saturated  solution  of  sodium  fluorid,  20  parts  to  one  part  of  a  commercial 
miscible  oil.  —  Pine  logs  were  dipped  and  sprayed  with  results  as  in  the  pre- 
vious experiment. 

Three  ounces  of  zinc  chlorid  dissolved  in  three  ounces  of  alcohol  and  added 
to  one  and  one-half  gallons  of  kerosene.  —  Pine  and  ash  sprayed  and  dipped. 
The  pine  was  attacked  after  30  days  by  insects  of  type  4  and  later  by  all  types. 
Ash  was  not  attacked  by  type  1.  June  1  the  treatment,  under  the  same  condi- 
tions, was  repeated  with  results  as  before. 

Five  and  ten  per  cent  crude  carbolic  acid  3  in  water.  —  Pine  logs,  sprayed  and 
dipped,  were  immediately  attacked  and  heavily  infested  by  all  types.  The 
final  results  were  no  better  than  with  the  controls. 

Two  and  one-half  per  cent  solution  crude  carbotic  acid  in  water,  eight  parts 
to  one  part  of  a  commercial  miscible  oil.—  Treatments  and  results  as  in  the  pre- 
ceding paragraph. 

Six  ounces  of  carbolic  acid  in  one  gallon  of  kerosene.  —  Pine,  sprayed  and 
dipped,  was  attacked  after  30  days  by  all  types.  The  final  results  were  no 
better  than  with  the  controls. 

3  Coal-tar  oils  and  acids,  97  per  cent  ;  inert  matter,  3  per  cent. 


10  BULLO^l.N'.  ]£79.   U...S.*  DEPARTMENT   OF   AGRICULTURE. 

Carbolic  soap  solution:  One  pint 'crude  Carbolic  acid  added  to  one  gallon  soft 
soap,  thinned  by  addition  of  one  gallon  of  hot  water,  left  to  stand  overnight,  and 
then  diluted  with  eight  gallons  of  soft  water  (recommended  in  literature). — 
Pine  and  ash,  sprayed  and  dipped  June  1,  were  attacked  by  all  types  after 
10  days. 

Five  per  cent  solution  of  nicotine  sulphate. — Pine,  hickory,  ash,  and  juniper 
were  sprayed,  and  all  were  attacked  by  type  4  within  10  days. 

Two  teaspoonfuls  nicotine  sulphate  dissolved  in  three  ounces  of  alcohol  and 
added  to  one  and  one-half  gallons  water. — Pine  and  ash,  sprayed  and  dipped, 
were  infested  by  all  types  after  15  days. 

Ten  per  cent  solution  of  sodium  carbonate. — Pine  and  hickory  logs  sprayed 
were  immediately  attacked  by  all  types  possible. 

Five  per  cent  solution  of  a  proprietary  crude  cresol-soap  disinfectant. — Pine, 
juniper,  ash,  and  hickory  were  sprayed  but  were  all  attacked  by  all  types 
possible. 

A  strong  suspension  of  whitewash. — Pine  logs  dipped  were  heavily  attacked 
after  the  first  rain. 

A  strong  solution  of  sodium  chlorid. — Pine  logs  sprayed  were  immediately 
attacked  and  their  condition  was  no  better  than  that  of  the  controls. 

One  part  crude  pyridin  preparation  to  ten  parts  water. — This  did  not  mix 
well.  Pine  and  ash  were  dipped  June  1.  After  30  days  both  woods  were 
infested  "by  all  types  possible,  but  were  in  somewhat  better  condition  than 
the  controls. 

One  part  crude  pyridin  preparation  to  ten  parts  kerosene. — Pine  and  ash 
were  dipped  June  1.  After  60  days  no  insects  had  attacked  either  wood. 
The  odor  could  still  be  detected  on  the  logs.  This  material  seems  to  be  very 
promising  and  deserves  further  trials. 

REMARKS  ON  POISONS  USED. 

Several  of  the  more  active  poisons  seem  to  be  effective  against 
certain  types  of  insects,  particularly  those  of  type  1.  They  are 
especially  effective  when  combined  with  oils  that  will  penetrate  the 
bark  (as  the  mixture  of  corrosive  sublimate  and  kerosene)  or  fol- 
lowed by  another  solution  rendering  them  insoluble  (as  arsenic  acid 
followed  by  lime  water).  This  latter,  however,  is  difficult  to  apply. 
They  are  also  more  effective  when  used  on  absorbent  types  of  bark 
as  ash  and  juniper. 

OTHER  EXPERIMENTS  WITH  INSECTS  OF  TYPE  3. 

The  results  of  the  preceding  treatments  were  not  conclusive  against 
the  ambrosia  beetles  (type  3)  for  two  reasons:  These  insects  require 
wood  that  is  moist — at  least  such  wood  presents  optimum  condi- 
tions— in  which  to  rear  their  broods.  The  logs  used  in  the  preced- 
ing experiments,  averaging  only  6  to  10  inches  in  diameter,  often 
dried  so  rapidly  that  they  were  not  suitable  for  these  beetles.  At  the 
same  time  another  series  of  experiments  was  being  conducted  in 
which  water-soaked  logs  were  used.  These  acted  as  traps,  attract- 
ing most  of  the  ambrosia  beetles. 


N 


EXPEEIMENTS  WITH  SPRA-Y  SpI^UTJO^g»fcF9R;GJlEHN  LOGS.          11 

Consequently,  to  determine  just  how  effective  these  solutions  were 
against  ambrosia  beetles  (Table  II), "the  water-soaked  logs  were 
thoroughly  sprayed  with  (1)  4  parts  kerosene  plus  1  part  creosote 
oil,  (2)  the  corrosive  sublimate  solution  as  given  before,  and  (3)  1 
part  crude  pyridin  preparation  to  8  parts  kerosene.  All  the  sticks 
were  dried  for  24  hours  before  the  sprays  were  applied.  These 
materials  were  applied  to  three  pines,  one  oak,  and  one  ash  log,  July 
28,  1920.  The  results  are  given  in  Table  II. 

TABLE  II. — Results  of  c-rpcrinictit^  in  the  treatment  of  water-soaked  logs 

(unhrosia  beetles.1 


Controls. 

Kerosene  and 
creosote  oil. 

Pyridin  and 
kerosene. 

Corrosive  sub- 
limate. 

Pin,- 

Oak. 

Ash. 

Pine. 

Oak. 

Ash. 

Pine. 

Oak. 

Ash. 

Pine. 

Oak. 

Ash. 

Aug.  3  ... 

1 
0 

1 

te 

la 
(') 
0 
(») 

(1)2 

1 
1 
3 

X 

13 
(") 

(«) 
(2) 

19 

7 
23 

27 

X 

64 

(2) 

8 

125 

0 
1 
0 
0 
1 
0 
3a 
0 
0 
2 

0 
0 
0 
0 
0 
0 
0 
0 
0 
0 

0 
0 
0 
1 
0 
0 
0 
2 
1 
4 

0 
0 
0 
0 
0 
0 
0 
0 
0 
0 

0 
0 
0 

0 
0 
0 
0 
0 
1 

0 
1 
0 
0 
0 
0 

0 
0 
2 

0 
0 
0 
la 
la 
0 
2a 
0 
0 
1 

0 
0 
5 
4 
0 
0 
1 
0 
0 
10 

1 
3 
6 
16 
10 
4 
7 
1 
4 
52 

g  9 

13 

22     .                

27 

Sept.  l         

8 

18 

28          

Total  ambrosia  beetles 

1  Numbers  refer  to  ambrosia  beetles  attacking  except  when  followed  by  letter. 
»  Not  counted. 

a=species  of  Ips,  type  4.     x=many  ambrosia  beetles  not  counted. 

POISONING   OF   AMBROSIA   BEETLES. 

To  determine  whether  ambrosia  beetles  feed  on  the  bark  as  they 
bore  through  it,  and  consequently  whether  poison  spray  could  be 
effective  against  them,  several  water-soaked  ash  logs  were  dried  for 
48  hours  to  remove  the  excess  water  from  the  bark  and  then  com- 
pletely submerged  for  48  hours  in  a  solution  of  sodium  arsenate,  2 
pounds  to  10  gallons  of  water. 

A  wooden  frame  with  a  cheesecloth  bottom  was  prepared  on  the 
ground,  and  on  supports  above  this  frame  a  rubber  cloth  was  sus- 
pended to  keep  any  rain  from  reaching  the  treated  sticks.  The  sticks 
were  placed  in  the  box  on  the  cheesecloth  and  the  cloth  was  carefully 
examined  every  two  or  three  days  for  dead  ambrosia  beetles.  The 
treatments  were  made  on  May  30,  1920.  An  untreated  control  was 
used  in  the  same  position.  The  results  were  as  follows: 

June  8,  one  dead  beetle  beneath  sticks. 

June  15,  one  beetle  boring  through  bark. 

June  23,  two  beetles  boring  through  bark. 

July  23,  two  to  six  beetles  were  in  each  stick  and  all  galleries  contained 
eggs  and  various  stages  of  larvae. 

These  beetles  were  evidently  not  deterred  or  injured  by  the  poison. 
At  no  time  were  the  sticks  wet.  It  is  quite  probable  that  the  dead 
beetle  found  June  8  was  not  killed  by  the  poison,  since  no  other  dead 
insects  were  found. 


Gaylord  Bros. 

Makers 

Syracuse,  N.  Y. 
PAT.  JAN.  21,  19G 


4  9  C.I 


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